Field of the Invention
The invention relates to a capsule for use in a device for preparing beverages. The invention also relates to an assembly of such a capsule and a device for preparing beverages. In addition, the invention relates to a perforation structure evidently intended for use in such a capsule according to the invention. The invention also relates to the use of such a capsule in a device for preparing beverages. The invention further relates to a sealing element for use in a capsule according to the invention.
Description of Related Art
Diverse capsules for use in a device for preparing beverages are known in the prior art. A known capsule as described for instance in EP 0512468 comprises a housing provided with a perforable supply side for injecting a liquid into the housing and with a discharge side located at a distance from the supply side and provided with an opening for the purpose of discharging liquid injected into the housing, a quantity of substance for extraction received in the housing, such as ground coffee beans, and a pierceable foil connected to the housing and sealing the opening located on the discharge side. This known capsule can be placed in a device for preparing a beverage. The capsule is placed for this purpose in a receiving space of a capsule holder of the device. The capsule is clampingly supported here in the receiving space by a support and a clamp. The supply side of a housing of the capsule is perforated by subsequently moving a liquid injector through the housing of the capsule, and a relatively hot liquid, in particular water, can be introduced into the housing under a relatively high pressure, generally of between 15 and 20 bar. The foil is perforated by moving a perforation plate forming part of the capsule holder and the capsule toward each other and the extracted liquid flows via the perforation plate into a beverage container. Because of the relatively high operating pressure a space between the capsule and capsule holder will generally be filled with a sealing element. In the case the sealing connection does not function in the correct manner and water flows outside the capsule, insufficient pressure will be developed inside the capsule to cause tearing of the foil or the pressure will not tear the foil completely, and this can impede the extraction process considerably. It is possible here to envisage providing the capsule holder with a sealing element in order to realize sealing. It is however generally more advantageous to provide the capsule with a sealing element, whereby the sealing element is used only once, whereby improved operation of the sealing element can be guaranteed. The European patent EP 1654966 describes a capsule which is provided on an outer side with a sealing element manufactured from a rubber-elastic material, in particular silicone rubber. Although the material properties of rubber-elastic materials are favourable for sealing engagement on the capsule holder, such rubber-elastic materials are found to be relatively difficult to produce, and it is moreover relatively difficult to attach the rubber-elastic sealing element to the capsule by means of welding. If the sealing element is insufficiently adhered to the capsule during welding, one or more leakages can occur between the sealing element and the capsule, which can result in leakage(s) during the extraction process. The sealing action of the capsule known from EP 1654966 is moreover greatly dependent on the shaping of the capsule holder and on possible damage to the rubber of the capsule.
An object of the invention is to provide an improved capsule with which at least one of the above stated drawbacks can be obviated.
A further object of the invention is to provide a capsule with an improved sealing element.